ImageActivity.java

package io.jari.dumpert.activities;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.ActivityOptionsCompat;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.nispok.snackbar.Snackbar;
import com.squareup.picasso.Callback;
import com.squareup.picasso.Picasso;
import io.jari.dumpert.R;
import org.apache.http.util.ByteArrayBuffer;
import pl.droidsonroids.gif.GifDrawable;
import pl.droidsonroids.gif.GifImageView;
import uk.co.senab.photoview.PhotoViewAttacher;

import java.io.*;
import java.net.URL;
import java.net.URLConnection;

/**
 * JARI.IO
 * Date: 12-12-14
 * Time: 14:50
 */
public class ImageActivity extends BaseActivity {

    void setTheme() {
        String theme = preferences.getString("theme", "green");

        if(theme.equals("green")) {
            //default theme, do nothing
        } else if(theme.equals("blue")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_Blue);
        } else if(theme.equals("red")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_Red);
        } else if(theme.equals("pink")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_Pink);
        } else if(theme.equals("orange")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_Orange);
        } else if(theme.equals("bluegray")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_BlueGray);
        } else if(theme.equals("webartisans")) {
            super.setTheme(R.style.Theme_Dumpert_NoActionBar_WebArtisans);
        }
    }

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //wait until data has loaded
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
            this.postponeEnterTransition();

        setContentView(R.layout.image);


        final String[] images = getIntent().getStringArrayExtra("images");

        ViewPager pager = (ViewPager)findViewById(R.id.viewpager);
        PagerAdapter pagerAdapter = new ImageAdapter(images);
        pager.setAdapter(pagerAdapter);

        this.tip();
    }

    public void download(String url, String fileName) throws IOException {  //this is the downloader method
        URLConnection ucon = new URL(url).openConnection();
        File file = new File(fileName);

        InputStream is = ucon.getInputStream();
        BufferedInputStream bis = new BufferedInputStream(is);

        ByteArrayBuffer baf = new ByteArrayBuffer(50);
        int current = 0;
        while ((current = bis.read()) != -1) {
            baf.append((byte) current);
        }


        FileOutputStream fos = new FileOutputStream(file);
        fos.write(baf.toByteArray());
        fos.close();
    }

    public void tip() {
        SharedPreferences sharedPreferences = getSharedPreferences("dumpert", 0);
        if(!sharedPreferences.getBoolean("seenImageTip", false)) {
            sharedPreferences.edit().putBoolean("seenImageTip", true).apply();

            Snackbar.with(getApplicationContext())
                    .text(getResources().getText(R.string.tip_touch_to_enlarge))
                    .actionLabel(getResources().getString(R.string.tip_close))
                    .actionColor(Color.parseColor("#D32F2F"))
                    .duration(4000)
                    .show(this);
        }
    }

    public static void launch(Activity activity, View transitionView, String[] images) {
        ActivityOptionsCompat options = ActivityOptionsCompat.makeSceneTransitionAnimation(activity, transitionView, "image");
        Intent intent = new Intent(activity, ImageActivity.class);
        intent.putExtra("images", images);
        ActivityCompat.startActivity(activity, intent, options.toBundle());
    }

    class ImageAdapter extends PagerAdapter {
        public String[] urls;

        public ImageAdapter(String[] urls) {
            this.urls = urls;
        }

        @Override
        public int getCount() {
            return urls.length;
        }

        @Override
        public View instantiateItem(ViewGroup container, int position) {
             final View view = LayoutInflater.from(ImageActivity.this)
                    .inflate(R.layout.image_image, container, false);
            final GifImageView imageView = (GifImageView)view.findViewById(R.id.image_image);

            if(position == 0) {
                ViewCompat.setTransitionName(imageView, "image");
            }

            final String image = urls[position];

            Picasso
                    .with(ImageActivity.this)
                    .load(image)
                    .into(imageView, new Callback() {
                        @Override
                        public void onSuccess() {
                            //attach photoview
                            new PhotoViewAttacher(imageView);

                            //the only way we can check if this is a gif, probably not more needed
                            if(image.endsWith(".gif")) {
                                final View loader = view.findViewById(R.id.image_loader);
                                loader.setVisibility(View.VISIBLE);

                                new Thread(new Runnable() {
                                    @Override
                                    public void run() {
                                        try {
                                            String file = getCacheDir().getPath() + "/" + Uri.parse(image).getLastPathSegment();
                                            download(image, file);

                                            final GifDrawable gif = new GifDrawable(file);

                                            //clean up
                                            new File(file).delete();

                                            runOnUiThread(new Runnable() {
                                                @Override
                                                public void run() {
                                                    imageView.setImageDrawable(gif);
                                                }
                                            });
                                        } catch (Exception e) {
                                            e.printStackTrace();
                                            Snackbar.with(ImageActivity.this)
                                                    .text(R.string.gif_failed)
                                                    .textColor(Color.parseColor("#FFCDD2"))
                                                    .show(ImageActivity.this);
                                        }
                                        finally {
                                            runOnUiThread(new Runnable() {
                                                @Override
                                                public void run() {
                                                    loader.setVisibility(View.GONE);
                                                }
                                            });
                                        }
                                    }
                                }).start();
                            }
                        }

                        @Override
                        public void onError() {

                        }
                    });

            container.addView(view);

            if(Build.VERSION.SDK_INT >= 21 && position == 0)
                startPostponedEnterTransition();

            return view;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((View) object);
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }

    }
}